The Collaborative International Dictionary of English v.0.48:

Harlequinade \Har"le*quin*ade`\ (-[=a]d`), n. [F. arleguinade.]
   A play or part of a play in which the harlequin is
   conspicuous; the part of a harlequin. --Macaulay.
   [1913 Webster]

WordNet (r) 3.0 (2006):

harlequinade
    n 1: acting like a clown or buffoon [syn: buffoonery,
         clowning, japery, frivolity, harlequinade, prank]